fun main(args : Array<String>){
    println("Hello world!")
    //字符
    val  value2: Char
    value2= 'A'

    val id = arrayOf(1,2,3,4,5)
    val firstId = id[0]
    val lasted = id[id.size-1]

    var value1 = 10
    val value3 = value1  // 编译错误，类型不匹配
    println("")

}